•    N5 G01 X-6 Y00 Z00 F120

•   N6 M05

•   N7 M02

Results and Discussion

Figure 18 shows the basic CNC lathe operations, in the figure the labelling 1, 2, 3, 4, 5 shows the plain turning, step turning, taper turning, arc turning and threading operations respectively. Based on the dimensional accuracy  achieved,

all the basic operations are satisfactory. Figure 19 shows the operations involved in the bolt manufacturing. Labelling 1, 2, 3 shows the threading, parting and the finished bolt respectively. Standard dimensions were selected for the bolt, and threads of 16 TPI were made. The workpiece was then parted accordingly and was finished in a sanding machine. To confirm the accuracy of manufacturing, the finished bolt (Fig. 19(3)) was checked with a nut. Perfect movement of the nut was achieved on the bolt.

All the operations are performed successfully, thus it establishes the success of the conceptual design and development of the lathe attachment for the CNC machine. The CNC machine can behave both as an RP as well as a Lathe with the respective attachment. Both the attachments operates on the same CNC machine, which in turn is operated by the same mechatronic controls and the same computer interface CAMSOFT. The design for the lathe attachment was challenging, when not to disturb the con- figuration of the CNC machine with respect to the RP attachment was the major constraint. To speak of the lathe attachment, the CNC lathe machine has four axes (X, Y, Z and a spindle). Here the tool is stationary and capable of moving vertically (due to Z axis movement), for the machining operation, longitudinal feed is achieved by the horizontal Y axis and with cross X axis, the bed (work- piece) comes to the tool in accordance with the depth of cut desired. The major advantage of the CNC lathe is with the tool post, for the parting operation, where a relatively small sized parting tool can be used to part a relative larger diameter workpiece (Fig. 19(3)), when the tool is given vertical motion from the Z axis. Thus the machine can be used to carry research work in the field of both CNC RP and CNC Lathe. So the present work shows the   relevance

Fig. 18 Basic lathe operations Note: 1. Plain Turning (Machined Surface: Length = 40 mm, Depth of Cut = 0.6 mm). 2. Step Turning (Machined  Surface:  Length = 40 mm,   Reduction   in   Diame- ter = 7 mm). 3. Taper Turning (Machined Surface: Length = 1.6 inch, Tapered up to 1.35 inch, Taper per inch = 0.094). 4. Arc论文网

Turning [Machined Surface: Length = 1.6 inch, Centre of curvature (right) = 0.2 inch]. 5. Threading (Machined Surface: Length = 1.7 inch, TPI = 16). (Last three operations has been done in inch mode for convenience)

J. Inst. Eng. India Ser. C (April–June 2013)   94(2):187–195 195

Fig. 19 Manufacturing of the bolt

of conceptual design in the development of a multifunction machine.

Conclusion

Conceptual design is successfully implemented in the proposed work for the development of the lathe attachment including headstock, tailstock and toolpost. The work shows the process of the conceptual design and use of appropriate process planning for the development of the different components of the lathe attachment. The previ- ously existing RP attachment and the so developed lathe attachment make the CNC machine multifunctional. Thus further research can be carried out in both the fields respectively. The CNC machine is based on the macha- tronic controls and the computer interface CAMSOFT. Various lathe operations viz. Plain turning, step turning, taper turning, arc turning, threading operations and manu- facturing of a bolt are successfully performed on the CNC machine, when installed with lathe attachment. The suc- cessful development of the lathe attachment for the CNC machine is done.